Thermal Management Module (TMM)
The Thermal Management Module valve (TMM) is a device that controls the coolant flow rate in order to adjust the coolant temperature. At initial start-up, the TMM regulates the coolant to flow only in the engine, which leads to quick engine warm-up and better fuel efficiency. When the coolant temperature rises, the TMM adjusts the valve to regulate the coolant temperature by controlling the coolant flow to the radiator or heater.